Why is linux a unix-like system?

Why is linux a unix-like system-general Linux technology-Linux technology and application information? For more information, see the following. Linux and unix have the same kernel and SHELL operations, which are called unix-like systems.

Freebsd can be called another version of unix. the kernel is similar to that of the original Unix Version written in assembly language. Some applications are written in a mix of interpreted languages and assembly languages called B.

Ken and Dennis first developed Unix in Bell Labs. At that time, AT&T, the UNIX owner, granted the Unix source code to academic institutions for research or teaching at a low or even free license, many organizations have expanded and improved the source code to form the so-called Unix "Variations )"

Linux was initially developed by a student named Linus using Unix as a prototype. It is a Unix class, which is an open source implementation method of Unix and has similar functions as Unix.

UNIX is a commercial software, and most UNIX systems are compatible with hardware, such as Sun's Solaris, IBM's AIX, and HP's HP-UX. Linux can run on multiple hardware platforms.

"Classes" are similar but different. Simply put, upper-layer interfaces are similar, and the underlying implementation is different.